This invention relates to a processing system, such as an exposure system or a thin film forming system, for example, for performing a certain process in a reduced pressure ambience.
X-ray exposure apparatuses using SR (synchrotron radiation) light are known. The SR light is attenuated largely in air and, to avoid this, a synchrotron ring and a beam port for emitting SR light are kept under vacuum. The SR light is directed through a blocking window (beryllium window) into an exposure apparatus in which a mask and a wafer are placed. Also, the mask and the wafer are desirably disposed in an exposure ambience of vacuum or reduced pressure helium and, thus, the exposure apparatus is desirably accommodated in a reduced pressure container.
FIG. 12 is a schematic view of a known type processing system. Denoted in the drawing at 1 is a process chamber of reduced pressure ambience in which a process such as an exposure process or a thin film forming process, for example, is performed. Denoted at 2 is a load-lock chamber. While not shown in the drawing, there are a pump and valves for gas supplying and discharging of these two chambers. Disposed between the two chambers are a gate valve 9 and a bellows 11. Closing the gate valve 9 is effective to maintain the pressures of the two chambers, respectively.
The process chamber 1 is supported through supporting members 8a and 8b by a first base table 3, while the load lock chamber 2 is supported thereby through supporting members 8c and 8d. The first base table 3 is provided with air mounts (air springs) 16 by which vibration from the floor can be intercepted. Within the process chamber 1, a second base table 4 is supported by supporting members 8e and 8f. Processing stage 12 and a conveying robot 13 are mounted on the second base table 4. Within the load lock chamber 2, a third base table 5 is supported by supporting members 8g and 8h. Sample holding table 14 for holding a sample such as a substrate, for example, is mounted on the third base table 5.
FIG. 13 is a schematic view of another processing system of known type. SR light is projected through a beam port having its inside maintained under ultra high vacuum and through a beryllium window 52, into a stage accommodating chamber 60 of reduced pressure helium ambience. Disposed within the stage accommodating chamber 60 is a base table 58 which supports a mask chuck 53 for holding a mask 54 through attraction as well as a stage 57 for positioning a wafer 55, held by a wafer chuck 56 through attraction, with respect to the mask 54. The base table 58 is supported by air mounts (air springs) 61 by which adverse effect of vibration of the beam port or of vibration of the floor can be reduced.
In the structure of FIG. 12, when the process chamber 1 and the load lock chamber 2 are evacuated to reduce the inside pressure, elastic deformation of each chamber may be cause by the pressure reduction. Such deformation may be transmitted to the components placed inside the chamber to damage the positional relationship of the components. It may adversely affect sample transfer precision.
It is accordingly a first object of the present invention to provide an improved system which is free from the problem described above. More specifically, it is an object of the present invention to provide a processing system or a device manufacturing method using such a system, wherein adverse effect of deformation of any one of plural chambers to the positional relationship of components accommodated in the chambers can be avoided.
On the other hand, the structure shown in FIG. 13 involves problems in relation to the provision of the air mounts 61 inside the reduced pressure ambience in the chamber 60. One problem is the possibility of that the reduced pressure ambience is damaged by air leakage from the air mount, for example. Also, the height of the air mount changes with a change in relative difference between the pressure inside the chamber 60 and the pressure of the air mount, and this causes a change in position of a component mounted. Further, since an exposure apparatus is supported within the chamber 60, deformation caused by the pressure reduction may be transmitted to the inside exposure apparatus through the air mount, resulting in a change in position or attitude of the processing apparatus.
It is accordingly a second object of the present invention to provide an improved system which is free from the problem described above. More specifically, it is an object of the present invention to provide a processing system or a device manufacturing method using the same, by which degradation of ambience within the chamber is prevented and by which any change in position or attitude of a processing apparatus accommodated in the chamber is prevented.
It is a third object of the present invention to provide a processing system having a plurality of chambers, by which a process such as a high precision exposure process or thin film forming process can be performed.
In accordance with an aspect of the present invention and to achieve the first or third object of the present invention, there is provided a processing system which comprises first and second chambers each accommodating a processing apparatus therein, the inside of each chamber being able to be kept gas tight, a coupling member for coupling the processing apparatuses accommodated in the chambers and elastic gas tight holding means for gas tightly sealing the portions between the coupling member and the first and second chambers.
In accordance with another aspect of the present invention and to achieve the second or third object of the present invention, there is provided a processing system which comprises a chamber for accommodating a processing apparatus therein, the inside of the chamber being able to be kept gas tight, a base for supporting the processing apparatus, air mount means for supporting the base and supporting means for supporting the chamber, wherein the air mount means are disposed outside the chamber. The base and the chamber are preferably connected to each other gas tightly.
A processing system according to a further aspect of the present invention comprises a first chamber, a second chamber connected to the first chamber, a third chamber connected to the second chamber, a coupling member for mutually coupling apparatuses accommodated in the first and second chambers, and a bellows for coupling the second and third chambers with each other.
In the present invention, an exposure process may preferably be performed to a sample accommodated in the first chamber. By using a processing system of the present invention, high precision devices may be manufactured.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.